变量生成正则

 <script>
            let a = ['123','asd']
            //允许中间有空格
              a = a.map(item => {
                let arr = item.split('').join('\ {0,}')
                return arr
            })
            //
            let str = "saldnkjasbdkjasd 123dasdasd4123sdasd11asd123daaaa"
            let  re = new RegExp(`(${a.join('|')})`,'ig')
           let res = str.replace(re, function(word, index,sss){
               console.log(word, index,sss,"index")
                return '<span id="bigkeyword" style="background:yellow;color:red;">' + word + '</span>'
            })
            
            console.log(res,"res")
        </script>